Ninety Australians are fighting with terrorist groups in Iraq and Syria, according to the Prime Minister. Thirty have returned to Australia, and at least 140 people in Australia are "actively supporting" extremist groups.

He also revealed that ASIO is currently investigating several thousand leads and persons of concern and that 400 of these are "high priority cases".

Analysis from The Drum

Mr Abbott has called on Parliament to quickly pass new data-retention laws, which would require phone and internet providers to keep metadata about calls and emails for two years.

A parliamentary inquiry into the laws is due to report on Friday and Mr Abbott wants them passed within weeks.

Opposition Leader Bill Shorten, who has repeatedly said Labor and Liberal "are in this together" in relation to counter-terrorism, has today cautioned against rushing the legislation through.

"Haste and confusion is never the friend of good, sensible security in the future," he said.

Mr Shorten said the Opposition would "engage constructively" with the Government over the measures announced today.

Personal freedom and community safety need to balance: Abbott

The Prime Minister's statement that the Government will pursue tougher laws around vilification and inciting hatred has triggered concern about the consequences for freedom of speech.

Conservative think tank the Institute of Public Affairs said it flies in the face of Mr Abbott's now abandoned plan to repeal parts of the nation's racial discrimination laws.

"There is the potential from the comments today that not only will we have less freedom of speech, but we'll have restrictions on what all of us can say and that is very alarming," spokesman John Roskam said.

Mr Roskam said the Prime Minister must spell out exactly what he is planning.

"There are already strong prohibitions on intimidation, threats of violence and so on, racial hatred is a vague and ambiguous term and if we are going to give government powers of this sort we have to understand exactly what we are going to prohibit," he said.

The earlier plan to rewrite the Racial Discrimination Act also prompted passionate debate on the Liberal Party backbench, with some MPs vowing to cross the floor in any push for the repeal of the laws.

Liberal Democrat senator David Leyonhjelm said restricting people's freedoms would not make them safer.

"Law enforcement and the risk to Australia should be targeted at individuals, not at groups," he said.

"Taking away the rights of all the rest of us, sacrificing a little liberty amongst all of us in the interests of safety, it's never worked."

And he linked the Prime Minister's statements on terrorism to questions within the Liberal Party over Mr Abbott's leadership.

"We simply do not know what facts were known by Immigration when they assessed [Sydney siege gunman Man Haron Monis] as a refugee in 1996, but to say that the system failed because 20 years later he turns out to be a bad egg, I think is just ludicrous."

Former national security legislation monitor Bret Walker also said there was no system failure in the lead up to the Sydney siege.

"A system doesn't fail because it did not predict something which was not reasonably predictable, and that's really what the departmental conclusions found," he said.

Mr Walker also had concerns the Government was framing the terror threat as being at crisis point.

"This is not anything in the nature of a so-called crisis, the point about counter terrorism [is] it's going to be continuing effort," Mr Walker said.

"There are not peak occasions where we can, for a very short time, trade away liberties for short-term protections. This is a permanent state of affairs and that's why the Prime Minister correctly says the debate about where to strike the balance has to be ongoing and is inevitable."

Annalee Pope only knew a handful of words of her language, Wakka Wakka, until she started her career in Indigenous language work. She has now played a big part in reviving and strengthening her language.